Answer:
12x + 15 = 15
Step-by-step explanation:
step 2
9x + 3x + 15 = 15 ( collect like terms on left side )
step 3
12x + 15 = 15
I believe you do 180 - 149 because it's a linear pair, it makes a t shape!!
For one thing lines in spherical geometry can have two intersections whereas in euclidean Geometry two lines can intersect at most once (unless they are coincident lines)